Indirect-lighting unit



w. A. DOREY INDIRECT LIGHTING UNI'I 2 Sheets-Sheet 1 Filed Nov. 6, 1920 hummus W. A. DOREY INDIRECT LIGHTING UNIT Filed Nov. 1920 2 Sheets-Sheet 2 a glNVENTOR 4 4 ATTORNEY/3 Tiqk.

Patented a. 30, 1923; Y

UNITED STATES PATENT OFFICE...

WILLIAM A. DOREY, 0F NEWARK OHIO, ASSIGNOR TO HOLOPHANE GLASS COMFANY, INQ, OF. NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

' INDIRECT-LIGHTING" UNIT.

I Application filed November 6, 1920. Serial No. 422,269.

To all whomit may concern:

Be it known that I, WILLLAM'AL Donnr, a

citizen of the United States, and resident of Newark, in the'-eounty of Licking and State 'of Ohio, have invented certa1n new and useful Improvements in Indirect-Light .ing Units, of which the following is a specification.

The object of the invention is to construct a prismatic indirect appliance which will give effective control of the light rays trans mitted through the reflecting member by means of prismatic glass and at the same time reduce the glare to a minimum. F igure 1 is a vertical crossisection of the device, Figure 2' is a: vertical cross sectionof a modication of the device. Fig. 3 is an ele-.

v vation of a modification and Fig. 4 is a sec:

tion through line 4-4 of Fig. 3, looking u ward. In Figure 1, 1 is the lamp. 2 is t e light "source considered in this case as a point. 3 is the interior reflector having a smooth interior surface 4 and upon its outer surface so. called double reflecting prisms 5, so constructedthat a ray of light from the light source within will be reflected back to the ceiling or upper walls.

A certain amount of light is not reflected bythe prismatic reflector but is transmitted through the prisms and is acted upon by the outer cover 6.v This cover has a smoothouter surface 7 and aprismatic interior 8 on its upper portion, the action of which is explained by following the various light rays in their course through the inner reflector 3. The lower portion of cover 6 has a decorative outer surface '10 and a fluted interior surface 9. The reflector 3 is provided with a flange 16 which rests upon the flange 17 of the ,cover 6 so that the two flanges can be held together by a metal bandor other suitablemeans. Typical beam 0 incident .on the upper part 11 of the reflec' tor has a component a? which is doubly refracted to the ceiling 'or walls in themanner set forth; Therother component is transmitted through the apex or sides of the risms in the direction of (r and is emitted in direction a after deviation by the' combined action of the interior prism .I8and the outer surface 7 of envelope 6.'2'A portion of typical beam b-inciden t on point 12 is doubly reflected in direction of b a second component passing through the glass in the direction b and emerging in dias 0 c" from typical beam rection 6 A portion of typical'beam c incident on point 13 is doubly refracted in the direction a. A second component passing through the glass in direction 0 is spread by the flutings on surface 10 into the emerging beam 0 to 0. Typical beam (1 beam-d so that it will tend to light up any possible shadow from the upper edge of the device. as c, c are spread and thus partially diffused and emitted at angles lower than ordinary view points. In this particular ex- The transmitted components such ample the prisms on the inner surface 8 of envelope 6 have faces 14 which are substantially vertical and act with the outer surface to refract light upward and upper faces 15 placed substantially parallel-with the adjacent light rays within the outer envelope. A very small portion of the light will be incident on faces 15 and such light as does strike them will in the main be refracted at very low angles or reflected upward in the general direction of transmitted components a and b Figure 2 is a modification of the device in which asmall reflector part is used. The two members are fastened together by screw and nut 19 and the opening between the two members at the upper edge is filled spread to the transmitted com onents, such v Typical beam 6" incident at polnt 12' has a transmit-T ted component b which, after passingintosurface 9' are etchedjto give the requisite the envelope strikes the outer surface 7' at such a great angle that a considerable ortion of it will not be transmitted in direotion 11 but will reflected in direction 6" pass-through the envelope 6 in downward directions. In this design the upper faces such as 15' of the prisms on surface 8 are reduced in a slope as the lower edge of surface 8' is approached, so that they will catch increased proportions of the rays transmitted through the reflector. Typical beam 0 has transmission component 6 which is incident on one of these upper surfaces by which it is refracted downward. in the direction 6 Typical beam d is similar to beam d in Figure 1.

While the art shows a reflector member facing upward, the present device diflers from such prior art in redirecting. the light which would otherwise cause glare so as to reduce the shadow at the edge of the cone of light passing direct from the lamp in upward directions and to increase the relative proportion of direct light below an angle of 60 with the nadir as compared with the quantity of light at high angles below the horizontal.

It is possible to vary the proportion of light transmitted in downward directions by varying the inclination of the upright surfaces 15 or by decreasing or increasing the relative area of the lower diflusing portion of the enevelope.

The outer cover has been shown as smooth on the exterior and the inner reflector as smooth on the interior, but this is not absolutely essential to the practice of my invention as these may have corrugations or colors thereon, as long as they do not interfere with the reflective and directional value of-the device. Fig. 3 shows an elevation and Fig. 4 a section through line 4-4 of Fig. 3, looking upward,.ol a modification in which the outer cover has radial flutings 29 r on its exteriorsurface'or a design the eleouter envelope.

ments of which are preferably but not necessarily radial. The inner surface of the outer cover is here also lightly etched or colored as ion as it does not interfere with the directiona efi'ect of the prismatic construction, and heavy etching, sand-blasting or coloring may be applied inside or out in the lower non-prismatic portion of the I claim 1. A device for indirect lighting consisting of a light source, an interior upwardly facing reflector having reflecting prisms on its outer surface anda separate shade surrounding the same, the reflector being neraeee adapted to reflect the major portion of light rays incident thereon upwardly in a zone about the axis of the fixture limited in angles by interference of the fixture and the body of the reflector, and the shade having on its inner surface horizontal light directmga prisms adapted to receive and direct lig t rays transmitted through the reflector at angles to obliterate the shadow formed by the edge of the reflector.

Q. A device for indirect lighting consisting of a li ht source, an interior upwardly facing re ector having reflectin prisms on its outer surface and a separate s ade surroundin the same, the reflector being adapted to re ect the major'portion of light rays incident thereon upwardly in a zone about the axis of the fixture limitedin angles by interterence of the fixture and the body of the reflector, and the shade having on its inner surface a zone of light directing prisms and a zone of light difiusing surface adapted to receive and direct light rays transmitted through the reflector, at angles to obliterate the shadow formed by the edge of the reflector. 1

3. A. device for indirect lighting consisting of a light source, an interior upwardly facing translucent reflector, a separate shade surrounding the same, and a flat ring spaced between the upper edges of the reflector and shadehaving an interior surface reflective of light, the reflector being adapted to reflect a portion of the light rays upwardly in a zone about the axis of the fixture limited in an le by interference of the fixture support flarin reflector and a separate shade surroun mg the same, the reflector having radial double reflecting prisms on its outer surface adapted to reflect a major portion of the light rays incident thereon upwardly in a zone about-the axis of the fixture limited in angle'by interference of the fixture and the body of the reflector, and the shade havin on its inner surface horizontal light rel racting prisms adapted to receive and direct light rays transmitted throu h the.

reflector at angles to obliterate the s adow formed by the edge of the reflector.

Signed at Newark, in the county of Licking and State of Ohio, this 25th day ofOctoher, A... D. 1920. 

